The first step is to make sure the "enable RemoteDesktop on this computer" is checked; after all, that is the most common problem judging from the vast assortment of web pages explaining Remote Desktop conenction. So, I open the System Properties and select the "Remote" tab:
As you can see, the checkbox is properly checked, and clicking the “Select Remote Users” button lets us determine which users are permitted to remote desktop connect to this server. I’m an administrator on my server, so we see the list below:
I already have access, so now let’s go over to the PC that will remote in to the server, fire up Remote Desktop Connection and make sure all is well.
What’s this? All is not well – we couldn’t connect. Now I can see that server is not doing much, so I doubt it is too busy to accept connections. We know Remote connections are enabled (see above), so that can’t be it. Network problems? Well, that covers a lot of ground. Check the Ethernet cables, they’re all plugged in nice and sound, and it doesn’t appear that the cat has chewed through them (yet – what is it with cats and Ethernet cables?). Just to be sure, I verify that I can ping the PC, the printer, the Internet; I think we can safely say we’ve got connectivity.
Trying again produces the same results, as you might expect. Since I am the administrator, we already know that contacting the administrator won’t do much good. Let’s try to reason this thing through. Outgoing connections (Internet, LAN printer) are working, but we’re not getting through from the PC to the server. Aha! FIREWALL! Let’s see how the Windows Firewall is configured. We’ve got the Firewall on (after all the scary warnings about dire consequences of turning it off, who could blame us?).
Selecting the “Exceptions” tab immediately shows us the problem: the Remote Desktop is not granted an exception, so it is being blocked by the firewall.
I check “Remote Desktop” and immediately the problem is resolved.
I read and re-read the Microsoft notes on Remote Desktop Connection, including the troubleshooting suggestions, and nowhere did I see this mentioned. Admittedly I didn’t check all 1.6 million hits on the web, but life is short!